Ubuntu 13.04 and bluez-5.8 configure: error: systemd system unit directory is required

I am using Mint 15 and ran into same problem while installing BlueZ 5.8. Googling found your exact question. To solve it, had to add --with-systemdsystemunitdir and --with-systemduserunitdir configure options. Since Mint and Ubuntu have much in common, you may find that it works for you too. The complete command line is below. You may want to leave out the --enable-experimental flag so you don't get experimental plugins.

./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-experimental --with-systemdsystemunitdir=/lib/systemd/system --with-systemduserunitdir=/usr/lib/systemd

Configure it without systemD. It will work like so:

./configure --disable-systemd